Beeper's business model is actually based on people wanting all their messaging services in one app so they're not always separated.
I don't like Beeper personally, but this kind of misunderstands what Beeper intends to do, which is bigger and more thoughtful than what Sunbird is doing, which is just iMessage.
I prefer Beeper because I don't need multiple other chat apps installed and grabbing my data.
Yes, you have to trust Beeper.
I personally found it when I was forced to use WhatsApp with my landlord, and refuse to install any meta apps on my phone. I've since linked Telegram and Discord.
Not to mention many of those apps require permissions to work, but I can easily deny them on Beeper and Beeper doesn't care.
Sunbird is more than iMessage isn't it? I had the beta installed for a little bit and it was messenger, sms, iMessage, and a few others that haven't used.
Once RCS support rolls out on the iPhone, any cross-platform chat will have all the same advantages and features as iMessage, including read receipts, typing indicators, and high-res image sharing. Why bother jumping through loopholes when you can get the same experience using the native chat app?
We will see if RCS brings the same features of iMessage (it’s not going to be 1:1) and without E2EE I’ll continue to talk to my Android friends on another platform anyway.